This is the text from the IRC log for the 13th June, with the addition of a sentence on the distinct and shared modes to cover interference:
1) Change syntax in 2.3.4
from:
<channelType name="ncname"
usage="once"|"unlimited"?
action="request-respond"|"request"|"respond"? >to:
<channelType name="ncname"
usage="once"|"distinct"|"shared"?
action="request-respond"|"request"|"respond"? >
2) Change:
The OPTIONAL attribute usage is used to restrict the number of times a Channel of this Channel Type can be used.
To:
The OPTIONAL attribute usage is used to constrain the way in which an instance of this Channel Type can be used. The values that can be used for this attribute are:
(1) "once"
Once applied to a channel type means that a channel instance of that type can be used once and once only for at most one interaction or can be passed to another role. When a channel instance of this type is passed the passer of the channel instance reliquishes (for outputting only) control of that instance and passes control to the receiver. A channel instance of this type MUST NOT be passed to more than one receiver at any one time.
(2) "distinct" (default usage mode)
Distinct applied to a channel type means that a channel instance of that type can be used multiple times by a participant within multiple interactions. When a channel instance of this type is passed the passer of the channel instance relinquishes (for outputting only) control of that instance passing the control to the receiver. A channel instance of this type MUST NOT be passed to more than one receiver. In this mode, a participant MUST NOT specify two or more concurrent interactions, for the same channel instance, with the same operation name.
(3) "shared"
Shared applied to a channel type means that a channel instance of that type can be used multiple times by multiple participants within multiple interactions. When a channel instance of this type is passed the participant passing the channel instance does not reliquish control. In this mode, a participant MUST NOT specify two or more concurrent interactions, for the same channel instance, with the same operation name.